Various abbreviations that appear in the specification and/or in the drawing figures are defined as follows:
3GPP third generation partnership project
UTRAN universal terrestrial radio access network
EUTRAN evolved UTRAN (LTE)
LTE long term evolution
Node B base station
eNB EUTRAN Node B (evolved Node B)
UE user equipment
EPC evolved packet core
MME mobility management entity
S-GW serving gateway
RRC radio resource control
AP access point
BS base station
CC central controller
CCCH common control channel
CSCF call state control function
EPS evolved packet system
GW gateway
HSS home subscriber server
D2D device-to-device
IP internet protocol
IMS IP multimedia subsystem
NAI network access identifier
NAS non-access stratum
PDN GW packet data network GW
SGSN serving gateway support node
RB resource block
SRB signaling radio bearer
SAE evolved system architecture
SIP session initiation protocol
TMSI temporary mobile subscriber identity
OFDMA orthogonal frequency division multiple access
CDMA code division multiple access
One specification of interest is 3GPP TS 36.300, V8.4.0 (2008-03), 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Access Network (E-UTRAN); Overall description; Stage 2 (Release 8). This system may be referred to for convenience as LTE Rel-8, or simply as Rel-8. Note that this is a stage 2 specification, and may not exactly describe the system as it is currently expected to be implemented. In general, the set of specifications given generally as 3GPP TS 36.xyz (e.g., 36.311, 36.312, etc.) may be seen as describing the entire Release 8 LTE system.
Of particular interest herein are the further releases of 3GPP LTE targeted towards future IMT-A systems, referred to herein for convenience simply as LTE-Advanced (LTE-A). Reference can be made to 3GPP TR 36.913, V0.0.6 (2008-05), 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Requirements for Further Advancements for E-UTRA (LTE-Advanced) (Release X).
FIG. 1A is based on FIG. 4 of 3GPP TS 36.300, and shows the overall architecture of the E-UTRAN (Rel. 8) system. The E-UTRAN system includes eNBs, providing the E-UTRA user plane (PDCP/RLC/MAC/PHY) and control plane (RRC) protocol terminations towards the UEs. The eNBs are interconnected with each other by means of an X2 interface. The eNBs are also connected by means of an S1 interface to an EPC, more specifically to a MME (Mobility Management Entity), by means of an S1-MME interface, as well as to a Serving Gateway (S-GW) by means of an S1-U interface. The S1 interface supports a many-to-many relation between MMEs/Serving Gateways and eNBs.
FIG. 1B is based on FIG. 4.2.1-1 of 3GPP TS 23.401 V8.0.0 (2007-12), Technical Specification 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access (Release 8), and shows the non-roaming architecture for 3GPP accesses. In addition to the S1-MME interface shown in FIG. 1A, there is also shown an S1-U interface to a serving gateway. The serving gateway is interfaced with the MME (S11 interface), with a SGSN (S4 interface), with UTRAN (S12 interface), and with a PDN gateway (S5 interface).
IMT-A comprises radio technologies that meet the requirements currently defined by ITU for radio technologies beyond IMT-2000 (year 2010 and beyond). 3GPP is currently defining a study item to prepare LTE-Advanced that meets the IMT-Advanced requirements. Competing technologies such as WiMAX are expected to define advanced versions of current standards to be IMT-Advanced technologies. For WiMAX, standardization of IMT-Advanced technology is currently taking place in the IEEE 802.16m task group.
Aspects of IMT-A may be expected to include D2D communication to enable new types of services, as well as flexible spectrum use (FSU) to increase the spectral efficiency in a multi-operator environment.
In previous wireless communication systems (e.g., GSM, UMTS) with a circuit switched architecture it was straightforward to detect D2D traffic, as the network elements (MSC) involved in the D2D setup are a part of the cellular core network. As a result the core network could readily check if both devices were in the same cell, or in adjacent cells, to request a measurement and to setup the D2D bearer.
In addition to GSM and UMTS, D2D has also been proposed or provided in other wireless communication technologies, for example in WLAN, Hiperlan/2, and Tetra.
Various US Patents and Patent Application Publications that generally relate in some respect to peer-to-peer and mobile-to-mobile communication include: 2006/0178148, 2006/0160544, U.S. Pat. Nos. 7,050,821, 6,904,055, 6,415,146, 6,047,178, 5,995,500 and 5,666,661.
An ability to provide D2D communication is not supported by E-UTRAN (Rel. 8).